1. Field of the Invention
This invention relates to photographic light meters which are held in the hand and are of the type known as incident light or spot meters.
2. Description of the Prior Art
Although there have been many developments in the electronic control of the exposure setting of photographic cameras, the light metering employed has always been of the reflected light variety. In this, the camera is set on the assumption that the subject being illuminated and to be photographed has average reflectance of 18%. If the subject does not have that average reflectance, the camera meter is "fooled" (to use the widely accepted jargon) and the user has to compensate using a combination of experience and guesswork. Incident light metering, as its name implies, measures the light falling on the subject and is not liable to the introduction of errors due to non-average reflectance. In spot metering, a very small part of the subject area is selected by the user to act as typical of the whole scene and the light reflected by that small area is measured and the value is used to set the camera. Until now, however, the camera has always had to be set manually after the readings of the incident light or spot meter have been obtained.